[PATCH] blktrace: only add a bounce trace when we really bounce
Currently we issue a bounce trace when __blk_queue_bounce() is called,
but that merely means that the device has a lower dma mask than the
higher pages in the system. The bio itself may still be lower pages. So
move the bounce trace into __blk_queue_bounce(), when we know there will
actually be page bouncing.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/bounce.c b/mm/bounce.c
index e4b62d2..643efbe 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -237,6 +237,8 @@
if (!bio)
return;
+ blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
+
/*
* at least one page was bounced, fill in possible non-highmem
* pages
@@ -291,8 +293,6 @@
pool = isa_page_pool;
}
- blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
-
/*
* slow path
*/